<u>Question 8</u>
a^2 + 7a + 12
= (a+3)(a+4)
When factorising a quadratic, the product of the two factors should equal the constant term (12), and the sum of the two factors should equal the linear term (7). To find the two factors, list out the factors of 12 (1x12, 2x6, 3x4) and identify the pair that adds up to 7 (3+4).
An alternative method if you get stuck during your exam would be to solve it algebraically using the quadratic formula and then write it in the factorised form.
a = (-7 +or- sqrt(7^2 - 4(1)(12)) / 2(1)
= (-7 +or- sqrt(1))/2
= -3 or -4
These factors are the negative of the values that would go in the brackets when written in factorised form, as when a = -3 the factor (a+3) would equal 0. (If it were positive 3 instead, then in the factorised form it would be a-3).
<u>Question 10</u>
-3(x - y)/9 + (4x - 7y)/2 - (x + y)/18
Rewrite each fraction with a common denominator so you can combine the fractions into one.
= -6(x - y)/18 + 9(4x - 7y)/18 - (x + y)/18
= (-6(x - y) + 9(4x - 7y) - (x + y)) /18
Expand the brackets and collect like terms.
= (-6x + 6y + 36x - 63y - x - y)/18
= (29x - 58y)/18
= 29/18 x - 29/9 y
Answer:
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Answer:
Step-by-step explanation:
if its 3 - 4/7 then it = 2 3/7
if its 3*-4/7 then it = -12/7 = - 1 5/7
Answer:
Step-by-step explanation:
9 - x ≤17
At some point you are going to have to turn the equation around. This would not normally be your first step, but this time it is better to start with it.
We won't do it directly. The best way to do it is to add x to both sides before you do anything else. This is not the usual way to solve these equations, but it's a good time to learn.
Inequality Rule: you must always solve for x. If it is -x then you are going to have to make an adjustment to get the x to be positive.
9 - x ≤ 17 Add x to both sides
9 - x+x ≤ 17 + x Combine
9 ≤ 17 + x Subtract 17 from both sides.
9 - 17 ≤ 17 - 17 + x
8 ≤ x
Notice that you have effectively changed the ≤ sign around, not because you have, but because the x reads differently now. It started out 9 - x ≤ 17 and when you finish solving it you get 8 is less than or equal to x. Entirely different.
nope they are not similar
as in order to say that triangles are similar their sides should be in proportion or angles to be equal but here
here only one angle is equal the other one is not
So they are not similar
